Institute of Electrical and Electronics Engineers (IEEE) 802.11 is a set of air interface specifications in wireless local area network developed for Dedicated Short Range Communication (DSRC) by IEEE Committee, which provides wireless network service based on a competition scheme. In IEEE 802.11 wireless network, before transmitting a data packet, a station (STA) or an access point (AP) needs to monitor a channel to determine whether the channel is clear, and if yes, experience a random back-off process. Or else, the STA or AP cannot transmit the data packet and needs to monitor the channel again.
When the channel is noisy and busy, communication efficiency may be relatively low. Furthermore, a sending terminal may be even blocked from obtaining channel resources for a long time. In such occasion, a request to send/clear to send (RTS/CTS) mechanism may be used when data is transmitted, so as to obtain the channel resources for a certain time period. As such effective communication may continue.
As stipulated in the RTS/CTS mechanism, before transmitting data, a sending terminal needs to broadcast a RTS message to apply for a using permission and a using duration of the channel. When the RTS message is received by a receiving terminal, the receiving terminal may allocate the using permission and the using duration of the channel for the sending terminal according to a current channel occupation situation and further broadcast a CTS message which includes the allocation. Other sending terminals in the communication environment may receive the RTS and CTS messages. The sending terminal which obtains the using permission may use the channel in a certain time period, while other sending terminals may no longer compete for occupation of the channel in the certain time period.
When the channel is relatively noisy, the RTS/CTS mechanism may be effective. However, when the channel is relatively clear, using the RTS/CTS mechanism may reduce an effective throughput rate.
In existing techniques, a retransmission frequency of a STA or an AP is used to determine whether it is necessary to deploy the RTS/CTS mechanism. When the retransmission frequency is relatively high and meets specific requirements, the STA or AP may use the RTS/CTS mechanism to clear a channel, to obtain channel resources for a certain time period. However, the retransmission frequency is only one indirect parameter which partially reflects a noisy level and a busy/clear state of the channel, and cannot reflect the noisy level and state of the channel entirely. Worse still, sometimes there is no relation between the retransmission frequency and the noisy level and state of the channel sometimes. That is to say, the existing techniques cannot reasonably determine whether to use the RTS/CTS mechanism, which may result in a low throughput rate.
In existing techniques, it is hard to determine whether to use the RTS/CTS mechanism according to a practical noisy level of the channel in time, and the throughput rate may be relatively low.